The functional vessels of human and animal bodies such as the esophagus, bile duct, and blood vessels occasionally become damaged or diseased. For example, the aortic wall can weaken, resulting in an aneurysm. Upon further exposure to hemodynamic forces, an aneurysm can rupture.
Endoluminal prostheses, such as stents and stent-grafts, may be used for treating damaged or diseased functional vessels. For example, a stent graft may be used for repairing abdominal and thoracic aortic aneurysms. Such a stent-graft is placed inside the vessel and provides some or all of the functionality of the original, healthy vessel.
One of the challenges of designing and using an endoluminal prosthesis is preventing migration of the prosthesis once it is placed in a body lumen. This challenge is particularly great when the environment in which the prosthesis is placed is subject to a continuous strain, such as by the pulsatile force of blood flow in the vasculature. When an endoluminal prosthesis is used, for example, to repair an aneurysm, migration of the device may result in endoleaks or inadequate exclusion of the aneurysm, and increased risk of aneurysm rupture.
Various devices have been proposed to address migration. For example, a prosthesis may comprise one or more anchor members, such as a barb or hook, that extends radially outward from the prosthesis and is configured to engage surrounding body tissue. Typically, such barbs or hooks may be attached to the prosthesis by, for example, sewing, gluing, wrapping, chemical bonding, welding, brazing, soldering, and the like.